The present invention relates to a decoder for decoding a radio frequency carrier wave modulated with data encoded according to an error-correcting coding system.
In a wireless communication path wherein signals are subject to fading, code errors are concentrated in the period of lowered electric field intensity of the received signal. So long as the electric field intensity is high, code errors do not occur. However, the conventional error-correcting code decoders (Reference is made, for instance, to the article by R. T. Chien, et al., entitled "Error Correction in a Radio-Based Data Communications System", published in the IEEE Transactions on Communications, pages 458-462, April 1975) have the disadvantage that due to an error bit having occurred during the period of the lowered field intensity, a bit received during the period of adequate electric field intensity tends to cause an erroneous correction.